The invention herein relates to the art of supplemental or add-on hot water heaters as might be interposed in the supply line between a conventional hot water heater or tank and a utility outlet as a kitchen or basin faucet. In the ordinary installation of hot water piping around the home or in various commercial and industrial locations, there is often an extended length of pipe or supply line between the hot water heater or other reserve supply of hot water and the utility outlet.
While there have been developed, generally speaking, a number of supplemental heating units for the purpose whereby should the principal hot water supply itself be of insufficiently high temperature at the tank due to excess draw or the like, an interposed unit has means to raise the temperature thereof prior to discharge at the faucet or other outlet. Such units as hitherto known for supplementing cool tank water range variably in size from relatively small "under-sink" units to larger installations providing a reserve or supplemental supply of hot water when desired, and quite generally provide heating means, usually an electric heating element, to effect the desired heating of supplemental water notwithstanding previous overdraw of the normally available hot water supply from the main tank or heater.
Illustrative prior art teachings of such units include but are not limited to Morrow U.S. Pat. No. 2,307,061, Ostherheld U.S. Pat. No. 2,377,440, Karlen U.S. Pat. No. 2,870,318, Flanders U.S. Pat. No. 3,952,182, or Fischer 3,381,110.
Such add-on units do not, however, address the problem of the unavoidable cooling of the standing hot water in the length of line between the tank and outlet during non-use of the line between tap utilizations. During such periods, there is no continous and replacement flow of freshly heated water from the tank into the line as it is drawn by the tap.
Efforts to shorten the running length of line, or, to protectively insulate the line length are not always practical or even possible. It is therefore, an object of the invention herein to provide an accommodator unit in general proximity to the outlet or tap which can maintain a relatively small supply of water appropriately heated which is first drawn on faucet usage, and with which the relatively cooled in-line standing water will admix at a remote location from the accomodator outlet to ensure adequate heat at the outlet, prior to arrival thereat of fresh hot water from the main supply as the in-line standing water and the accommodator water are drawn down.